The invention relates to a fuel injection system for internal combustion engines. More particularly, the invention relates to a fuel injection system for a Diesel engine in which a high-pressure fuel injection pump is equipped with compensating mechanisms operating under servo control of an electronic controller. The electronic controller takes into account one or several engine variables to adjust the fuel injection mechanism to account for the magnitude of engine variables such as, for example, engine temperature. There are known in the art control mechanisms for changing the adjustment of a fuel injection pump on the basis of temperature or for limiting the position of a member within the fuel injection pump of a Diesel engine on the basis of operational variables such as air temperature. The known control systems use the signal related to air temperature to perform an additive correction of the position which is set within the fuel injection pump, i.e., the position of the fuel control rack is adjusted by an amount related to the air temperature. However, the increasingly rigorous laws relating to exhaust gas emissions cannot be satisfied with mechanisms of this type which base their correction on a single engine variable. In order to permit the correct mixture of air and fuel, it is required urgently to perform a compensation on the basis of both air and fuel temperature.